[JFFS2] Fix and improve debugging output during scan.
[linux-2.6.git] / fs / jffs2 / scan.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright (C) 2001-2003 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  * $Id: scan.c,v 1.125 2005/09/30 13:59:13 dedekind Exp $
11  *
12  */
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/pagemap.h>
18 #include <linux/crc32.h>
19 #include <linux/compiler.h>
20 #include "nodelist.h"
21 #include "summary.h"
22 #include "debug.h"
23
24 #define DEFAULT_EMPTY_SCAN_SIZE 1024
25
26 #define noisy_printk(noise, args...) do { \
27         if (*(noise)) { \
28                 printk(KERN_NOTICE args); \
29                  (*(noise))--; \
30                  if (!(*(noise))) { \
31                          printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \
32                  } \
33         } \
34 } while(0)
35
36 static uint32_t pseudo_random;
37
38 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
39                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
40
41 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
42  * Returning an error will abort the mount - bad checksums etc. should just mark the space
43  * as dirty.
44  */
45 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
46                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
47 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
48                                  struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
49
50 static inline int min_free(struct jffs2_sb_info *c)
51 {
52         uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
53 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
54         if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
55                 return c->wbuf_pagesize;
56 #endif
57         return min;
58
59 }
60
61 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
62         if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
63                 return sector_size;
64         else
65                 return DEFAULT_EMPTY_SCAN_SIZE;
66 }
67
68 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
69 {
70         int ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size);
71         if (ret)
72                 return ret;
73         /* Turned wasted size into dirty, since we apparently 
74            think it's recoverable now. */
75         jeb->dirty_size += jeb->wasted_size;
76         c->dirty_size += jeb->wasted_size;
77         c->wasted_size -= jeb->wasted_size;
78         jeb->wasted_size = 0;
79         if (VERYDIRTY(c, jeb->dirty_size)) {
80                 list_add(&jeb->list, &c->very_dirty_list);
81         } else {
82                 list_add(&jeb->list, &c->dirty_list);
83         }
84         return 0;
85 }
86
87 int jffs2_scan_medium(struct jffs2_sb_info *c)
88 {
89         int i, ret;
90         uint32_t empty_blocks = 0, bad_blocks = 0;
91         unsigned char *flashbuf = NULL;
92         uint32_t buf_size = 0;
93         struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
94 #ifndef __ECOS
95         size_t pointlen;
96
97         if (c->mtd->point) {
98                 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
99                 if (!ret && pointlen < c->mtd->size) {
100                         /* Don't muck about if it won't let us point to the whole flash */
101                         D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
102                         c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
103                         flashbuf = NULL;
104                 }
105                 if (ret)
106                         D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
107         }
108 #endif
109         if (!flashbuf) {
110                 /* For NAND it's quicker to read a whole eraseblock at a time,
111                    apparently */
112                 if (jffs2_cleanmarker_oob(c))
113                         buf_size = c->sector_size;
114                 else
115                         buf_size = PAGE_SIZE;
116
117                 /* Respect kmalloc limitations */
118                 if (buf_size > 128*1024)
119                         buf_size = 128*1024;
120
121                 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
122                 flashbuf = kmalloc(buf_size, GFP_KERNEL);
123                 if (!flashbuf)
124                         return -ENOMEM;
125         }
126
127         if (jffs2_sum_active()) {
128                 s = kmalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
129                 if (!s) {
130                         JFFS2_WARNING("Can't allocate memory for summary\n");
131                         return -ENOMEM;
132                 }
133                 memset(s, 0, sizeof(struct jffs2_summary));
134         }
135
136         for (i=0; i<c->nr_blocks; i++) {
137                 struct jffs2_eraseblock *jeb = &c->blocks[i];
138
139                 /* reset summary info for next eraseblock scan */
140                 jffs2_sum_reset_collected(s);
141
142                 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
143                                                 buf_size, s);
144
145                 if (ret < 0)
146                         goto out;
147
148                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
149
150                 /* Now decide which list to put it on */
151                 switch(ret) {
152                 case BLK_STATE_ALLFF:
153                         /*
154                          * Empty block.   Since we can't be sure it
155                          * was entirely erased, we just queue it for erase
156                          * again.  It will be marked as such when the erase
157                          * is complete.  Meanwhile we still count it as empty
158                          * for later checks.
159                          */
160                         empty_blocks++;
161                         list_add(&jeb->list, &c->erase_pending_list);
162                         c->nr_erasing_blocks++;
163                         break;
164
165                 case BLK_STATE_CLEANMARKER:
166                         /* Only a CLEANMARKER node is valid */
167                         if (!jeb->dirty_size) {
168                                 /* It's actually free */
169                                 list_add(&jeb->list, &c->free_list);
170                                 c->nr_free_blocks++;
171                         } else {
172                                 /* Dirt */
173                                 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
174                                 list_add(&jeb->list, &c->erase_pending_list);
175                                 c->nr_erasing_blocks++;
176                         }
177                         break;
178
179                 case BLK_STATE_CLEAN:
180                         /* Full (or almost full) of clean data. Clean list */
181                         list_add(&jeb->list, &c->clean_list);
182                         break;
183
184                 case BLK_STATE_PARTDIRTY:
185                         /* Some data, but not full. Dirty list. */
186                         /* We want to remember the block with most free space
187                         and stick it in the 'nextblock' position to start writing to it. */
188                         if (jeb->free_size > min_free(c) &&
189                                         (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
190                                 /* Better candidate for the next writes to go to */
191                                 if (c->nextblock) {
192                                         ret = file_dirty(c, c->nextblock);
193                                         if (ret)
194                                                 return ret;
195                                         /* deleting summary information of the old nextblock */
196                                         jffs2_sum_reset_collected(c->summary);
197                                 }
198                                 /* update collected summary information for the current nextblock */
199                                 jffs2_sum_move_collected(c, s);
200                                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
201                                 c->nextblock = jeb;
202                         } else {
203                                 ret = file_dirty(c, jeb);
204                                 if (ret)
205                                         return ret;
206                         }
207                         break;
208
209                 case BLK_STATE_ALLDIRTY:
210                         /* Nothing valid - not even a clean marker. Needs erasing. */
211                         /* For now we just put it on the erasing list. We'll start the erases later */
212                         D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
213                         list_add(&jeb->list, &c->erase_pending_list);
214                         c->nr_erasing_blocks++;
215                         break;
216
217                 case BLK_STATE_BADBLOCK:
218                         D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
219                         list_add(&jeb->list, &c->bad_list);
220                         c->bad_size += c->sector_size;
221                         c->free_size -= c->sector_size;
222                         bad_blocks++;
223                         break;
224                 default:
225                         printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
226                         BUG();
227                 }
228         }
229
230         /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
231         if (c->nextblock && (c->nextblock->dirty_size)) {
232                 c->nextblock->wasted_size += c->nextblock->dirty_size;
233                 c->wasted_size += c->nextblock->dirty_size;
234                 c->dirty_size -= c->nextblock->dirty_size;
235                 c->nextblock->dirty_size = 0;
236         }
237 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
238         if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
239                 /* If we're going to start writing into a block which already
240                    contains data, and the end of the data isn't page-aligned,
241                    skip a little and align it. */
242
243                 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
244
245                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
246                           skip));
247                 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
248                 jffs2_scan_dirty_space(c, c->nextblock, skip);
249         }
250 #endif
251         if (c->nr_erasing_blocks) {
252                 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
253                         printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
254                         printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
255                         ret = -EIO;
256                         goto out;
257                 }
258                 jffs2_erase_pending_trigger(c);
259         }
260         ret = 0;
261  out:
262         if (buf_size)
263                 kfree(flashbuf);
264 #ifndef __ECOS
265         else
266                 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
267 #endif
268         if (s)
269                 kfree(s);
270
271         return ret;
272 }
273
274 int jffs2_fill_scan_buf (struct jffs2_sb_info *c, void *buf,
275                                 uint32_t ofs, uint32_t len)
276 {
277         int ret;
278         size_t retlen;
279
280         ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
281         if (ret) {
282                 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
283                 return ret;
284         }
285         if (retlen < len) {
286                 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
287                 return -EIO;
288         }
289         return 0;
290 }
291
292 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
293 {
294         if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
295             && (!jeb->first_node || !ref_next(jeb->first_node)) )
296                 return BLK_STATE_CLEANMARKER;
297
298         /* move blocks with max 4 byte dirty space to cleanlist */
299         else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
300                 c->dirty_size -= jeb->dirty_size;
301                 c->wasted_size += jeb->dirty_size;
302                 jeb->wasted_size += jeb->dirty_size;
303                 jeb->dirty_size = 0;
304                 return BLK_STATE_CLEAN;
305         } else if (jeb->used_size || jeb->unchecked_size)
306                 return BLK_STATE_PARTDIRTY;
307         else
308                 return BLK_STATE_ALLDIRTY;
309 }
310
311 #ifdef CONFIG_JFFS2_FS_XATTR
312 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
313                                  struct jffs2_raw_xattr *rx, uint32_t ofs,
314                                  struct jffs2_summary *s)
315 {
316         struct jffs2_xattr_datum *xd;
317         uint32_t totlen, crc;
318         int err;
319
320         crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
321         if (crc != je32_to_cpu(rx->node_crc)) {
322                 if (je32_to_cpu(rx->node_crc) != 0xffffffff)
323                         JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
324                                       ofs, je32_to_cpu(rx->node_crc), crc);
325                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
326                         return err;
327                 return 0;
328         }
329
330         totlen = PAD(sizeof(*rx) + rx->name_len + 1 + je16_to_cpu(rx->value_len));
331         if (totlen != je32_to_cpu(rx->totlen)) {
332                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
333                               ofs, je32_to_cpu(rx->totlen), totlen);
334                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
335                         return err;
336                 return 0;
337         }
338
339         xd = jffs2_setup_xattr_datum(c, je32_to_cpu(rx->xid), je32_to_cpu(rx->version));
340         if (IS_ERR(xd)) {
341                 if (PTR_ERR(xd) == -EEXIST) {
342                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rx->totlen)))))
343                                 return err;
344                         return 0;
345                 }
346                 return PTR_ERR(xd);
347         }
348         xd->xprefix = rx->xprefix;
349         xd->name_len = rx->name_len;
350         xd->value_len = je16_to_cpu(rx->value_len);
351         xd->data_crc = je32_to_cpu(rx->data_crc);
352
353         xd->node = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
354         /* FIXME */ xd->node->next_in_ino = (void *)xd;
355
356         if (jffs2_sum_active())
357                 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
358         dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
359                   ofs, xd->xid, xd->version);
360         return 0;
361 }
362
363 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
364                                 struct jffs2_raw_xref *rr, uint32_t ofs,
365                                 struct jffs2_summary *s)
366 {
367         struct jffs2_xattr_ref *ref;
368         uint32_t crc;
369         int err;
370
371         crc = crc32(0, rr, sizeof(*rr) - 4);
372         if (crc != je32_to_cpu(rr->node_crc)) {
373                 if (je32_to_cpu(rr->node_crc) != 0xffffffff)
374                         JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
375                                       ofs, je32_to_cpu(rr->node_crc), crc);
376                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
377                         return err;
378                 return 0;
379         }
380
381         if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
382                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
383                               ofs, je32_to_cpu(rr->totlen),
384                               PAD(sizeof(struct jffs2_raw_xref)));
385                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
386                         return err;
387                 return 0;
388         }
389
390         ref = jffs2_alloc_xattr_ref();
391         if (!ref)
392                 return -ENOMEM;
393
394         /* BEFORE jffs2_build_xattr_subsystem() called, 
395          * ref->xid is used to store 32bit xid, xd is not used
396          * ref->ino is used to store 32bit inode-number, ic is not used
397          * Thoes variables are declared as union, thus using those
398          * are exclusive. In a similar way, ref->next is temporarily
399          * used to chain all xattr_ref object. It's re-chained to
400          * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
401          */
402         ref->ino = je32_to_cpu(rr->ino);
403         ref->xid = je32_to_cpu(rr->xid);
404         ref->next = c->xref_temp;
405         c->xref_temp = ref;
406
407         ref->node = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), NULL);
408         /* FIXME */ ref->node->next_in_ino = (void *)ref;
409
410         if (jffs2_sum_active())
411                 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
412         dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
413                   ofs, ref->xid, ref->ino);
414         return 0;
415 }
416 #endif
417
418 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
419    the flash, XIP-style */
420 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
421                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
422         struct jffs2_unknown_node *node;
423         struct jffs2_unknown_node crcnode;
424         uint32_t ofs, prevofs;
425         uint32_t hdr_crc, buf_ofs, buf_len;
426         int err;
427         int noise = 0;
428
429
430 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
431         int cleanmarkerfound = 0;
432 #endif
433
434         ofs = jeb->offset;
435         prevofs = jeb->offset - 1;
436
437         D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
438
439 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
440         if (jffs2_cleanmarker_oob(c)) {
441                 int ret = jffs2_check_nand_cleanmarker(c, jeb);
442                 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
443                 /* Even if it's not found, we still scan to see
444                    if the block is empty. We use this information
445                    to decide whether to erase it or not. */
446                 switch (ret) {
447                 case 0:         cleanmarkerfound = 1; break;
448                 case 1:         break;
449                 case 2:         return BLK_STATE_BADBLOCK;
450                 case 3:         return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */
451                 default:        return ret;
452                 }
453         }
454 #endif
455
456         if (jffs2_sum_active()) {
457                 struct jffs2_sum_marker *sm;
458                 void *sumptr = NULL;
459                 uint32_t sumlen;
460               
461                 if (!buf_size) {
462                         /* XIP case. Just look, point at the summary if it's there */
463                         sm = (void *)buf + jeb->offset - sizeof(*sm);
464                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
465                                 sumptr = buf + je32_to_cpu(sm->offset);
466                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
467                         }
468                 } else {
469                         /* If NAND flash, read a whole page of it. Else just the end */
470                         if (c->wbuf_pagesize)
471                                 buf_len = c->wbuf_pagesize;
472                         else
473                                 buf_len = sizeof(*sm);
474
475                         /* Read as much as we want into the _end_ of the preallocated buffer */
476                         err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
477                                                   jeb->offset + c->sector_size - buf_len,
478                                                   buf_len);                             
479                         if (err)
480                                 return err;
481
482                         sm = (void *)buf + buf_size - sizeof(*sm);
483                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
484                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
485                                 sumptr = buf + buf_size - sumlen;
486
487                                 /* Now, make sure the summary itself is available */
488                                 if (sumlen > buf_size) {
489                                         /* Need to kmalloc for this. */
490                                         sumptr = kmalloc(sumlen, GFP_KERNEL);
491                                         if (!sumptr)
492                                                 return -ENOMEM;
493                                         memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
494                                 }
495                                 if (buf_len < sumlen) {
496                                         /* Need to read more so that the entire summary node is present */
497                                         err = jffs2_fill_scan_buf(c, sumptr, 
498                                                                   jeb->offset + c->sector_size - sumlen,
499                                                                   sumlen - buf_len);                            
500                                         if (err)
501                                                 return err;
502                                 }
503                         }
504
505                 }
506
507                 if (sumptr) {
508                         err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
509
510                         if (buf_size && sumlen > buf_size)
511                                 kfree(sumptr);
512                         /* If it returns with a real error, bail. 
513                            If it returns positive, that's a block classification
514                            (i.e. BLK_STATE_xxx) so return that too.
515                            If it returns zero, fall through to full scan. */
516                         if (err)
517                                 return err;
518                 }
519         }
520
521         buf_ofs = jeb->offset;
522
523         if (!buf_size) {
524                 /* This is the XIP case -- we're reading _directly_ from the flash chip */
525                 buf_len = c->sector_size;
526         } else {
527                 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
528                 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
529                 if (err)
530                         return err;
531         }
532
533         /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
534         ofs = 0;
535
536         /* Scan only 4KiB of 0xFF before declaring it's empty */
537         while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
538                 ofs += 4;
539
540         if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
541 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
542                 if (jffs2_cleanmarker_oob(c)) {
543                         /* scan oob, take care of cleanmarker */
544                         int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
545                         D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
546                         switch (ret) {
547                         case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
548                         case 1:         return BLK_STATE_ALLDIRTY;
549                         default:        return ret;
550                         }
551                 }
552 #endif
553                 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
554                 if (c->cleanmarker_size == 0)
555                         return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
556                 else
557                         return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
558         }
559         if (ofs) {
560                 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
561                           jeb->offset + ofs));
562                 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
563                         return err;
564         }
565
566         /* Now ofs is a complete physical flash offset as it always was... */
567         ofs += jeb->offset;
568
569         noise = 10;
570
571         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
572
573 scan_more:
574         while(ofs < jeb->offset + c->sector_size) {
575
576                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
577
578                 /* Make sure there are node refs available for use */
579                 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
580                 if (err)
581                         return err;
582
583                 cond_resched();
584
585                 if (ofs & 3) {
586                         printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
587                         ofs = PAD(ofs);
588                         continue;
589                 }
590                 if (ofs == prevofs) {
591                         printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
592                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
593                                 return err;
594                         ofs += 4;
595                         continue;
596                 }
597                 prevofs = ofs;
598
599                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
600                         D1(printk(KERN_DEBUG "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", sizeof(struct jffs2_unknown_node),
601                                   jeb->offset, c->sector_size, ofs, sizeof(*node)));
602                         if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
603                                 return err;
604                         break;
605                 }
606
607                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
608                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
609                         D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
610                                   sizeof(struct jffs2_unknown_node), buf_len, ofs));
611                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
612                         if (err)
613                                 return err;
614                         buf_ofs = ofs;
615                 }
616
617                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
618
619                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
620                         uint32_t inbuf_ofs;
621                         uint32_t empty_start;
622
623                         empty_start = ofs;
624                         ofs += 4;
625
626                         D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
627                 more_empty:
628                         inbuf_ofs = ofs - buf_ofs;
629                         while (inbuf_ofs < buf_len) {
630                                 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
631                                         printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
632                                                empty_start, ofs);
633                                         if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
634                                                 return err;
635                                         goto scan_more;
636                                 }
637
638                                 inbuf_ofs+=4;
639                                 ofs += 4;
640                         }
641                         /* Ran off end. */
642                         D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
643
644                         /* If we're only checking the beginning of a block with a cleanmarker,
645                            bail now */
646                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
647                             c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
648                                 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
649                                 return BLK_STATE_CLEANMARKER;
650                         }
651
652                         /* See how much more there is to read in this eraseblock... */
653                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
654                         if (!buf_len) {
655                                 /* No more to read. Break out of main loop without marking
656                                    this range of empty space as dirty (because it's not) */
657                                 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
658                                           empty_start));
659                                 break;
660                         }
661                         D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
662                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
663                         if (err)
664                                 return err;
665                         buf_ofs = ofs;
666                         goto more_empty;
667                 }
668
669                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
670                         printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
671                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
672                                 return err;
673                         ofs += 4;
674                         continue;
675                 }
676                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
677                         D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
678                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
679                                 return err;
680                         ofs += 4;
681                         continue;
682                 }
683                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
684                         printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
685                         printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
686                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
687                                 return err;
688                         ofs += 4;
689                         continue;
690                 }
691                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
692                         /* OK. We're out of possibilities. Whinge and move on */
693                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
694                                      JFFS2_MAGIC_BITMASK, ofs,
695                                      je16_to_cpu(node->magic));
696                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
697                                 return err;
698                         ofs += 4;
699                         continue;
700                 }
701                 /* We seem to have a node of sorts. Check the CRC */
702                 crcnode.magic = node->magic;
703                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
704                 crcnode.totlen = node->totlen;
705                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
706
707                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
708                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
709                                      ofs, je16_to_cpu(node->magic),
710                                      je16_to_cpu(node->nodetype),
711                                      je32_to_cpu(node->totlen),
712                                      je32_to_cpu(node->hdr_crc),
713                                      hdr_crc);
714                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
715                                 return err;
716                         ofs += 4;
717                         continue;
718                 }
719
720                 if (ofs + je32_to_cpu(node->totlen) >
721                     jeb->offset + c->sector_size) {
722                         /* Eep. Node goes over the end of the erase block. */
723                         printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
724                                ofs, je32_to_cpu(node->totlen));
725                         printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
726                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
727                                 return err;
728                         ofs += 4;
729                         continue;
730                 }
731
732                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
733                         /* Wheee. This is an obsoleted node */
734                         D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
735                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
736                                 return err;
737                         ofs += PAD(je32_to_cpu(node->totlen));
738                         continue;
739                 }
740
741                 switch(je16_to_cpu(node->nodetype)) {
742                 case JFFS2_NODETYPE_INODE:
743                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
744                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
745                                 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
746                                           sizeof(struct jffs2_raw_inode), buf_len, ofs));
747                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
748                                 if (err)
749                                         return err;
750                                 buf_ofs = ofs;
751                                 node = (void *)buf;
752                         }
753                         err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
754                         if (err) return err;
755                         ofs += PAD(je32_to_cpu(node->totlen));
756                         break;
757
758                 case JFFS2_NODETYPE_DIRENT:
759                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
760                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
761                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
762                                           je32_to_cpu(node->totlen), buf_len, ofs));
763                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
764                                 if (err)
765                                         return err;
766                                 buf_ofs = ofs;
767                                 node = (void *)buf;
768                         }
769                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
770                         if (err) return err;
771                         ofs += PAD(je32_to_cpu(node->totlen));
772                         break;
773
774 #ifdef CONFIG_JFFS2_FS_XATTR
775                 case JFFS2_NODETYPE_XATTR:
776                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
777                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
778                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
779                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
780                                           je32_to_cpu(node->totlen), buf_len, ofs));
781                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
782                                 if (err)
783                                         return err;
784                                 buf_ofs = ofs;
785                                 node = (void *)buf;
786                         }
787                         err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
788                         if (err)
789                                 return err;
790                         ofs += PAD(je32_to_cpu(node->totlen));
791                         break;
792                 case JFFS2_NODETYPE_XREF:
793                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
794                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
795                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
796                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
797                                           je32_to_cpu(node->totlen), buf_len, ofs));
798                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
799                                 if (err)
800                                         return err;
801                                 buf_ofs = ofs;
802                                 node = (void *)buf;
803                         }
804                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
805                         if (err)
806                                 return err;
807                         ofs += PAD(je32_to_cpu(node->totlen));
808                         break;
809 #endif  /* CONFIG_JFFS2_FS_XATTR */
810
811                 case JFFS2_NODETYPE_CLEANMARKER:
812                         D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
813                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
814                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
815                                        ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
816                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
817                                         return err;
818                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
819                         } else if (jeb->first_node) {
820                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
821                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
822                                         return err;
823                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
824                         } else {
825                                 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
826
827                                 ofs += PAD(c->cleanmarker_size);
828                         }
829                         break;
830
831                 case JFFS2_NODETYPE_PADDING:
832                         if (jffs2_sum_active())
833                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
834                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
835                                 return err;
836                         ofs += PAD(je32_to_cpu(node->totlen));
837                         break;
838
839                 default:
840                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
841                         case JFFS2_FEATURE_ROCOMPAT:
842                                 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
843                                 c->flags |= JFFS2_SB_FLAG_RO;
844                                 if (!(jffs2_is_readonly(c)))
845                                         return -EROFS;
846                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
847                                         return err;
848                                 ofs += PAD(je32_to_cpu(node->totlen));
849                                 break;
850
851                         case JFFS2_FEATURE_INCOMPAT:
852                                 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
853                                 return -EINVAL;
854
855                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
856                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
857                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
858                                         return err;
859                                 ofs += PAD(je32_to_cpu(node->totlen));
860                                 break;
861
862                         case JFFS2_FEATURE_RWCOMPAT_COPY: {
863                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
864
865                                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
866
867                                 /* We can't summarise nodes we don't grok */
868                                 jffs2_sum_disable_collecting(s);
869                                 ofs += PAD(je32_to_cpu(node->totlen));
870                                 break;
871                                 }
872                         }
873                 }
874         }
875
876         if (jffs2_sum_active()) {
877                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
878                         dbg_summary("There is not enough space for "
879                                 "summary information, disabling for this jeb!\n");
880                         jffs2_sum_disable_collecting(s);
881                 }
882         }
883
884         D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
885                   jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
886         
887         /* mark_node_obsolete can add to wasted !! */
888         if (jeb->wasted_size) {
889                 jeb->dirty_size += jeb->wasted_size;
890                 c->dirty_size += jeb->wasted_size;
891                 c->wasted_size -= jeb->wasted_size;
892                 jeb->wasted_size = 0;
893         }
894
895         return jffs2_scan_classify_jeb(c, jeb);
896 }
897
898 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
899 {
900         struct jffs2_inode_cache *ic;
901
902         ic = jffs2_get_ino_cache(c, ino);
903         if (ic)
904                 return ic;
905
906         if (ino > c->highest_ino)
907                 c->highest_ino = ino;
908
909         ic = jffs2_alloc_inode_cache();
910         if (!ic) {
911                 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
912                 return NULL;
913         }
914         memset(ic, 0, sizeof(*ic));
915
916         ic->ino = ino;
917         ic->nodes = (void *)ic;
918         jffs2_add_ino_cache(c, ic);
919         if (ino == 1)
920                 ic->nlink = 1;
921         return ic;
922 }
923
924 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
925                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
926 {
927         struct jffs2_inode_cache *ic;
928         uint32_t ino = je32_to_cpu(ri->ino);
929         int err;
930
931         D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
932
933         /* We do very little here now. Just check the ino# to which we should attribute
934            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
935            we used to scan the flash once only, reading everything we want from it into
936            memory, then building all our in-core data structures and freeing the extra
937            information. Now we allow the first part of the mount to complete a lot quicker,
938            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
939            Which means that the _full_ amount of time to get to proper write mode with GC
940            operational may actually be _longer_ than before. Sucks to be me. */
941
942         ic = jffs2_get_ino_cache(c, ino);
943         if (!ic) {
944                 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
945                    first node we found for this inode. Do a CRC check to protect against the former
946                    case */
947                 uint32_t crc = crc32(0, ri, sizeof(*ri)-8);
948
949                 if (crc != je32_to_cpu(ri->node_crc)) {
950                         printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
951                                ofs, je32_to_cpu(ri->node_crc), crc);
952                         /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
953                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(ri->totlen)))))
954                                 return err;
955                         return 0;
956                 }
957                 ic = jffs2_scan_make_ino_cache(c, ino);
958                 if (!ic)
959                         return -ENOMEM;
960         }
961
962         /* Wheee. It worked */
963         jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
964
965         D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
966                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
967                   je32_to_cpu(ri->offset),
968                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
969
970         pseudo_random += je32_to_cpu(ri->version);
971
972         if (jffs2_sum_active()) {
973                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
974         }
975
976         return 0;
977 }
978
979 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
980                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
981 {
982         struct jffs2_full_dirent *fd;
983         struct jffs2_inode_cache *ic;
984         uint32_t crc;
985         int err;
986
987         D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
988
989         /* We don't get here unless the node is still valid, so we don't have to
990            mask in the ACCURATE bit any more. */
991         crc = crc32(0, rd, sizeof(*rd)-8);
992
993         if (crc != je32_to_cpu(rd->node_crc)) {
994                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
995                        ofs, je32_to_cpu(rd->node_crc), crc);
996                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
997                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
998                         return err;
999                 return 0;
1000         }
1001
1002         pseudo_random += je32_to_cpu(rd->version);
1003
1004         fd = jffs2_alloc_full_dirent(rd->nsize+1);
1005         if (!fd) {
1006                 return -ENOMEM;
1007         }
1008         memcpy(&fd->name, rd->name, rd->nsize);
1009         fd->name[rd->nsize] = 0;
1010
1011         crc = crc32(0, fd->name, rd->nsize);
1012         if (crc != je32_to_cpu(rd->name_crc)) {
1013                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1014                        ofs, je32_to_cpu(rd->name_crc), crc);
1015                 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1016                 jffs2_free_full_dirent(fd);
1017                 /* FIXME: Why do we believe totlen? */
1018                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1019                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1020                         return err;
1021                 return 0;
1022         }
1023         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1024         if (!ic) {
1025                 jffs2_free_full_dirent(fd);
1026                 return -ENOMEM;
1027         }
1028
1029         fd->raw = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rd->totlen)), ic);
1030
1031         fd->next = NULL;
1032         fd->version = je32_to_cpu(rd->version);
1033         fd->ino = je32_to_cpu(rd->ino);
1034         fd->nhash = full_name_hash(fd->name, rd->nsize);
1035         fd->type = rd->type;
1036         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1037
1038         if (jffs2_sum_active()) {
1039                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1040         }
1041
1042         return 0;
1043 }
1044
1045 static int count_list(struct list_head *l)
1046 {
1047         uint32_t count = 0;
1048         struct list_head *tmp;
1049
1050         list_for_each(tmp, l) {
1051                 count++;
1052         }
1053         return count;
1054 }
1055
1056 /* Note: This breaks if list_empty(head). I don't care. You
1057    might, if you copy this code and use it elsewhere :) */
1058 static void rotate_list(struct list_head *head, uint32_t count)
1059 {
1060         struct list_head *n = head->next;
1061
1062         list_del(head);
1063         while(count--) {
1064                 n = n->next;
1065         }
1066         list_add(head, n);
1067 }
1068
1069 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1070 {
1071         uint32_t x;
1072         uint32_t rotateby;
1073
1074         x = count_list(&c->clean_list);
1075         if (x) {
1076                 rotateby = pseudo_random % x;
1077                 rotate_list((&c->clean_list), rotateby);
1078         }
1079
1080         x = count_list(&c->very_dirty_list);
1081         if (x) {
1082                 rotateby = pseudo_random % x;
1083                 rotate_list((&c->very_dirty_list), rotateby);
1084         }
1085
1086         x = count_list(&c->dirty_list);
1087         if (x) {
1088                 rotateby = pseudo_random % x;
1089                 rotate_list((&c->dirty_list), rotateby);
1090         }
1091
1092         x = count_list(&c->erasable_list);
1093         if (x) {
1094                 rotateby = pseudo_random % x;
1095                 rotate_list((&c->erasable_list), rotateby);
1096         }
1097
1098         if (c->nr_erasing_blocks) {
1099                 rotateby = pseudo_random % c->nr_erasing_blocks;
1100                 rotate_list((&c->erase_pending_list), rotateby);
1101         }
1102
1103         if (c->nr_free_blocks) {
1104                 rotateby = pseudo_random % c->nr_free_blocks;
1105                 rotate_list((&c->free_list), rotateby);
1106         }
1107 }